id: CVE-2021-44528

info:
  name: Open Redirect in Host Authorization Middleware
  author: geeknik
  severity: medium
  description: Specially crafted "X-Forwarded-Host" headers in combination with certain "allowed host" formats can cause the Host Authorization middleware in Action Pack to redirect users to a malicious website.
  reference:
    - https://seclists.org/oss-sec/2021/q4/att-160/7-0-host-authorzation-open-redirect.patch
    - https://nvd.nist.gov/vuln/detail/CVE-2021-44528
    - https://github.com/rails/rails/commit/0fccfb9a3097a9c4260c791f1a40b128517e7815
  classification:
    cvss-metrics: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
    cvss-score: 6.1
    cve-id: CVE-2021-44528
    cwe-id: CWE-601
  tags: cve,cve2021,redirect

requests:
  - raw:
      - |
        GET / HTTP/1.1
        Host: {{Hostname}}
        X-Forwarded-Host: //example.com

    matchers-condition: and
    matchers:
      - type: regex
        part: header
        regex:
          - '(?m)^(?:Location\s*?:\s*?)(?:https?:\/\/|\/\/|\/\\\\|\/\\)?(?:[a-zA-Z0-9\-_\.@]*)example\.com\/?(\/|[^.].*)?$'

      - type: status
        status:
          - 301
          - 302
          - 307
          - 308

# Enhanced by mp on 2022/02/28